DOS disk interface is quite mundante. It was dependant on BIOS recognition, and its not compatible with 32 GB disk at all. An 120MB or 250MB HDD was the usual MS-DOS disk sold during the 6.22 era. The firsts GB disk ware common by 1996. By the way, 2GB is the max recognizable partition size. Use fdisk to create a Master Boot Record, and a 2GB partition, and try it. I tried it with ease with old 1 GB and 512MB Compact Flash cards, but I must say CF has almost direct compatibility with IDE. SD cards require an adapter controller (you seems to have one of those, tho).